Earlier quoted context omitted.
I suppose the ethical question would be: how many current humans are you willing to let die from exposure to a virus in the hopes that one of them might mutate something useful?
It's really an impossible calculation. There's no way to appraise the consequences to assign a value. If it were possible to say, that a future mutation was necessary to save humanity (ie. we are doomed without entering that future) well then perhaps we'd be willing to sacrifice a lot of us now. It's all academic of course, we'll never make such a decision, and never know what could have been. It's just another remin…
Even in that scenario, it is very simple, we protected the people today and use vaccines to induce the necessary mutation. The moral choice in my book is to always err on the side of the living than "potential of the living".